Process of deamination of primary aromatic amines



Patented May 9, 1933 UNITED STATES PATENT OFFICE .ALPlZ-ONS 0. JAEGER, FGRAFTON, PENNSYLVANIA, ASSIGN OR TO THE SELDEN COM- PANY, OF PITTSBURGH,PENNSYLVANIA, A CGRPORATION OF DELAWARE PROCESS OF DEAMINATION PRIMARYAROIMATIG AMINES N0 Drawing.

This invention relates to deaminations of primary aromatic amines.

According to the present invention amino groups are split from organiccompounds, particularly in the vapor phase by means of a new class ofcontact masses. The contact masses used in the present invention containbase exchange bodies or their derivatives. Under the term base exchangebody are included all natural or artificial bodies which possess theproperties of exchanging their bases for other bases of salt solutions.The base exchanging products used in making catalytic compositions ofthe present invention or as initial material for derivatives to be soused may possess high base exchanging power or in many cases may possesslower base exchanging power, since the catalytic value of the finalcompositions is not primarily dependent on the amount of base exchangingpower present. In general the base exchange bodies may be divided intotwo main categories :Two-component and multi-component zeolites, i. e.,base exchange bodies containing chemically combined s1licon in theirnucleus and non-silicious base exchange bodies in which all of thesilicon is replaced by other suitable acidic or amphoteric metal oxides.Two-component zeolites are the reaction products of two types of initialcomponents, that is to say, metallates and silicates, (using the termmetallat-e in a somewhat broader sense as will be defined further on inthe description), or metal salts and silicates. Frequently more than.one member of a type may enter into reaction, that is to say a silicatemay react with more than one metallate or more than one metal salt. Themulti-component zeolites are the reaction products of at leastthreetypes of components, that is to say, at least one silicate, at least onemetallate, and at least one metal salt.

The base exchange bodies, both zeolites and non-silicious base exchangebodies, may be associated with diluents preferably in the form of aphysically homogeneous structure, as will be described below. Eitherdiluted or undiluted base exchange bodies may be present in the contactmasses used in the Application filed April 1929. Serial No. 351,828.

present invention, or their derivatives may be present, but it should beunderstood that wherever base exchange bodies are referred to bothdiluted and undiluted products are included. a

Base exchange bodies, both zeolites and non-silieious base exchangebodies, may also be transformed into derivatives which possess many ofthe chemical and most of the physical characteristics ofthe parent baseexchange bodies. Such derivatives may be salt-like bodies, that is tosay, the reaction products of base exchange bodies with compoundscontaining anions capable of reacting with the base exchange bodies toform products which possess many of the properties of salts. A furtherclass of derivatives are the acid leached base exchange'bodies. When abase exchange body is subjected to leaching by acids, particularlydilute mineral acids, the exchangeable base are first gradually removed.The resulting products contain both the more basic and more acidiccomponents of the non-exchangeable nucleus of the base exchange body,with or without a portion of the exchangeable bases. As the leaching iscarried on further, more and more of the relatively positive componentsof the non-exchangeable nucleus are removed, and if carried tocompletion the leached product contains only the relativelyacidcomponents of the non-exchangeable nucleus. In the case of zeolitesthe final product from long continued leaching is a complex silicic acidwhich has many of the physical properties of the original base exchangebody. In the description and claims the class of base exchange bodiesand their derivatives will be referred to by the generic termpermutogenetic products.

Catalytically active components may be associated with diluted orundiluted permutogenetic bodies in four main forms, as follows :(1) Theymay be physically admixed with or impregnated into the permutogeneticproducts. (2) They may be physically, homogeneously incorporated intothe permutogenetic products before the latter have been completelyformed in the form of catalytically active diluent bodies or in the formof bined with the base exchange bodies in the form of catalyticallyactive anions which form with the base exchange body salt-like bodies.l) They may be chemically combined in exchangeable form either duringthe formation of the base exchange body or by base exchange afterformation. Obviously of course the same or dilferent catalyticallyactive component may be present in more than one of the above describedforms, and it an advantage of thepresent invention that catalyticallyactive substances may be introduced in a wide variety of forms whichgives a large field of choice to the catalytic chemist.

While the ditlerent permutogenetic prod ucts may vary widely in theirchemical characteristics, they all possess a similar physical structurewhich is characterized by more or less high porosity, frequentlymicroporosity, and great resistance to high temperatures, and in thecase of products which have not been acid leached the point of removal.of catalytically. active components these components are distributedthroughout the framework of the products in atomic or moleculardispersion, as will be described in greater detail below, and thischemical homogeneity is one of the important advantages of some of thecontact masses of the present invention.

lVhile three ofthe methods of combination of the catalytically activesubstances may be effected with undiluted as well as dilutedpermutogenetic products, it has been found that for most deaminationreactions homo geneous- V ly diluted permutogenetic contact masses areof advantage, particularly where the dilucnts are of a physical naturesuch as to exert a desired influence on a catalytic activity of thecontact masses, as when, for example, diluents are rich in silica, whichh been found to have an activating power, or where the diluents byreason of high porosity, capillarity, or surface energy may beconsidered as physical catalysts or activators.

Base exchange bodies used in contact masses of the present inventionbehave as if they were products of extremely high molecular weight forcatalytically active components can be introduced either into thenonexchangeable nucleus or in the form of exchangeable bases inpractically any desirable proportions and the ordinary law of chemicalcombining proportions, which in compounds of low molecular weightrestricts the proportlons in which components can be incapable ofstructural chemical analysis. The present invention is of course notlimited to any theory, but irrespective of the underlying reasons thefact that catalytically active components may be chemically introducedin any desired proportions is of enormous importance to the catalyticchemist and gives him the power to produce an almost unlimited number offinely and gradually toned catalysts or contact masses for thedeamidation of organic compounds and in all cases the contact massesproduced are highly effective by reason of'the desirable physicalstructure of the permutogenetic products contained therein and the widelimits of homogeneous dilution of catalytically active molecules oratoms with resulting uniformity and smoothness of action, which is ofgreat importance,

particularly in the sensitive reactions for which contact masses used inthe present invention are peculiarly adapted.

V In addition to the important characteristics with. whichpermutogenetic products endow the contact masses of the presentinvention,

it has been found that for many of the re-'- actions coming within thescope of the present invention it is desirable to stabilize the contactmasses,and thismay be effected by associating with the permutogeneticproducts or incorporating or forming therein compounds of the alkaliforming metals, that is to say, the alkali metals and the alkaline earthmetals. These compounds appear to slow up or smooth out the catalyticreaction, and

willbe referred to throughout this specificaa tion as stabilizers. Thestabilizers may be non-alkaline, weakly alkaline or strongly alkaline,depending on the reaction products and on the nature of thecatalytically active components used. It is a great advantage of thepresent invention that in the normal formation of base exchange bodiesalkali forming metal oxides are present as exchangeable bases, andwhether used without acid treatment or treated with acid, they formstabilizers which are combined in or associated with the resultingpermutogenetic products in an extremely fine state of division in whichthe stabilizers are peculiarly active. base exchange bodies containingalkali forming metal exchangeable bases may be considered as complexstabilizers.

In addition to the use of stabilizers, which are important in a largenumber of splitting reactions included in the scope of the present Thus,

erably in the presence of fluxes.

invention, it has been found that the stabilizer action and the overallelficiency of the contact masses can in many cases be greatly increasedor enhanced by the association therewith or chemical combination thereinof elements or radicals or groups which are catalytically active but donot possess specific catalytic activity for the particular reaction tobe carried out. Many reactions are aided by the presence of catalystsfavoring other types of reactions, such as oxidations, reductions, andthe like which are not specific de- 'amidation catalysts. Such catalystsor catalytic components which are not specific catalysts for thereaction in which they are being used under the reactionconditions obtaining Wlll be referred to throughout the specification as stabilizerpromoters, as they:

appear to enhance the toning eiiect which'can be achieved bystabilizers. The use of this expression should, however, in no sense betaken to limit the expression to a particular theory of action of thesenon-specific catalysts and in fact in some cases stabilizer pro motersmay be present where there are not stabilizers.

The tremendous range of chemical groups which may be combined in or withor incorporated in permutogenetic products permits a wide choice ofstabilizer promoters as well as specific catalysts, and permits theirassociation with the contact masses in an extremely homogeneous andcatalytically efiicient form. Thus, many base exchange bodies or theirderivatives may be considered as complex catalysts, stabilizers andstabilizer promoters, as all of these elements may be present in thesame chemical compound and sharing the advantages flowing from itsdesirable physical structure and chemical properties. Of course bothstabilizer and stabilizer promoters may be mixed partly or wholly withpermutogenetic products and a single stabilizer or single stabilizerpromoter may be present partly in physical admixture and partly inchemical combination, as will be clear to the skilled base exchangechemist.

The base exchange bodies which form the important components or initialmaterial for derivatives in contact masses of the present invention maybe prepared by any of the well known methods. Thus, for example,twocomponent zeolites may be prepared by wet methods in which themetallate components or metal salt components, part or all ofwhich maybecatalytically active, are caused to react with soluble silicates to formzeolites of alumino silicate or aluminum double silicate types, or thecomponents may be fused, pref- It should be understood that under theterm metallate is included not only the alkaline solutions of amphotericmetal oxides or hydroxides but also alkali forming metal salts of metalacids,

" such as the oxyacids of metals of the fifth and the formation oftwo-component zeolites by wet methods, the final reaction product mustbe alkaline to litmus, and for productsof high base exchanging power itshould be neutral or alkaline to phenolphthalein. For theJpurpose ofproducing base exchange bodies to be used in the preparation of-contactmasses of" the present invention it is sometimes unnecessary to providehigh base exchanging power, and for many purposes zeolites formed underconditions resulting in a final reaction which is acid tophenolphthalein but alkaline to lit mus are of advantage. It is notdefinitely known whether products produced under such curcumstances arehomogeneous chemical compounds, although in many ways they behave assuch. There is, however, reason to believe that in some cases at leastmixtures of base exchanging and non-base exchanging polysilicates may beproduced. For the purpose of the present specification a product will beconsidered as a base exchange product, if it has any base exchange powerat all.

It is desirable for many purposes, and particularly where two-componentzeolites of high base exchanging power are needed, to add the relativelyacid components, for example, metal salts in the case of aluminum doublesilicate type of silicates, to the lrelatively more alkaline componentssuch as, for example, soluble silicates. By these means a continuousalkalinity is insured, and this method may be considered as thepreferred method in most cases, but the opposite procedure isadvantageous for certain contact masses and is included in theinvention.

Multi-component' zeolites may be prepared by any of the foregoingmethods using at least three types of components, that is to say, atleast one metallate, at least one metal salt and atleast one solublesilicate. In the case of multi-component' zeolites, as in the caseoftwo-component zeolites, the conditions of alkalinity should beobserved,and for many purposes it is advantageous to add. theerelativelyacid components to the relatively alhaline components in order to insurecontmu ous alkaline reaction. The multi-component zeolites produced varyin their nature, depending on the proportion of the different reactingcomponents. Thus, where the metallatesand silicates predominate over themetal salts the resulting products resemble the alumino silicate type oftwo component zeolites; if the metal salts and silicates predominateover the metallates the products resemble the aluminum double silicatetype of two-com-- 1 ;ponent zeolites; and, finally if the metallatesbodies briefly described above, natural base and metal salts predominateover the silicates the resulting product resembles more or lessnon-silicious base exchange bodies. It will be clear that there is nosharp defining line between the three types of multi-component zeolites,and one shades into the other as the proportions of thediflerentcomponents vary. It is an advantage of the multi-component zeolites overthe two-component zeolites that the choice of catalytically activecomponents I is wider, as some'catalytically active elements or groupscan only be'incorporated in the form of metallates and others only inthe form of metals salts. In the multi-component zeoliteseachcatalytically active group can be incorporated in the form in which itis best available.

I Non-silicious base exchange bodies are produced by the general methodsdescribed above, but instead of bringing about reactions betweensilicates and other metal oxide com- -pon-ents, two or more oxymetalcompounds are caused to react; in general, at least one will be ametallate and at leastone a metal salt, or in some cases it is possibleto bring about action between two different metallates in which onenegative radical is more acidic than the other. It is possible toproduce nonsilicious base exchange bodies in which a plurality of metaloxides is present. It is also possible to produce non-silicious baseexchange bodies in which a single metal is present. Thus, for example,some metals may be sufficiently amphoteric in character to form bothmetallates and metal salts which are capable of reacting with each otherto produce base exchange bodies. 7 Y

A special method of producing nonsilicious base exchange bodies consistsin the gradual neutralization of strongly alkaline salts'of the oxyacidsof metal elements of the fifth and sixth groups in stages of oxidationin which they are sufiiciently amphoteric. The neutralization of otherstrongly alkaline metallates may also bring about formation ofnon-silicious base exchange bodies. The converse method, wherebynon-alkaline salts of suitable metals are gradually treated with alkaliuntil the reaction is sufficiently alkaline to permit the formation ofbase exchange bodies, may also be used.

Many metals are capable of entering into the base exchange formationonly in certain stages of oxidation, and it is sometimes necessary tointroduce such metals in a stage of oxidation different from thatdesired in the final base exchange body, the change of I stage ofoxidation being preferably effected during the'formation of the baseexchange body. Certain other elements may be incorporated in the form ofcomplex compounds of the most various types, such as, for example,ammonia complexes and the like.

In addition to. the artificial base exchange exchange bodies, such asnepheline, leucite, felspar, and the like, may be used.

The most important contact masses for many deamidation reactions containpermutogenetic products in which preferably the diluents arehomogeneously incorporated into the base exchange bodies beforeformation of the latter, or at least before the base exchange body hasset after formation. Many diluents such as inert, stabilizing,activating, catalytica-lly active, or having stabilizer promotereffects, can be used. A few of the diluents will be briefly enumeratedkieselguhrs of allkinds, particularly natural or treated Celite earth;silicious pow- .ders of various types; powdered permutogenetic products;natural or artificlal pow acre of rocks, stones, tufts, trass, lava, andsimilarly volcanic products which are frequently highly porous;greensand; glauconite or its acid leached derivative glaucosil;pulverized slag'wool; cements; sand; silicia gel; pulverizedearthenware; fullers earth; talc; glass powder; pumice meal; as-

bestos; graphite; activated carbon-;fquartz meal; various pulverizedminerals rich in quarts; metal powders and metal alloy powdcrs; salts ofoxymetal acids such as tungstates, vanadates, chromates, uranates,manganates, cerates, molybz'lates, etc, and particularly copper salts ofthe above; silicates, such as copper silicate, iron silicate, nickelsilicate,cobalt silicate, aluminum silicate; titanium silicate; mineralsor ores,'especially those rich in copper, etc. Finely divided diluentsare of great advantage, especially when the average particle size isless than 60 microns, in which case the diluents possess high surfaceenergy which increases the adsorptive and absorptive capacity of thecontact mass, the diffusion speed and porosity. These finely divideddiluents may be considered as physical catalysts or activators. Dilutedpermutogenetic bodies may also be finely divided and used as part or allof the dilnents of other base exchange bodies.

The following nine methods-are the most etfective'for the introductionof diluent-s, but any other suitable methods can be used.

{1) The dilnents may be mixed with one or more liquid components of thebase exchange bodies to be formed when the latter are pre pared by wetmethods. 7

(2) Components, either ca tive. stabilizer promoters, or ot precipitatedor impregnated. i. bodies which are then incorporated into the baseexchange bodies by any suitable methods of incorporation.

(3) Diluents may be mixed with base e change bodies when the latter arestill in the form of gels by kneading or stirring, in which case thebase exchange gel behaves as an adhesive. The homogeneity anduniformityof the distribution of the diluents is of course not quite sogreat by this method as by Method (1), but for the deamination of'organic compounds extreme uniformity is not essential.

(4) Diluents may be formed during the formation of the base exchangebodies by mixing suitable compounds with the components of the baseexchange bodies so that the diluent particles are precipitated duringformation. Protective colloids may be added to prevent coagulation ofthe diluent particles before the base exchange. bodies have becomesufficiently set.

(5) Compounds may be added which react with'certain of the base exchangebodies forming components to produce diluents, for instance salts of themetal acids of the fifth and sixth groups may be added in sufficientexcess so that they react with components of the base exchange body toform insoluble diluents, as, for example, with heavy metal oxides.

(6) Preformed base exchange bodies, diluted or undiluted, artificial ornatural, can be impregnated with true or colloidal solutions ofcatalytically effective components and then dried.

(7) A preformed base exchange body, di

luted or undiluted, may be impregnated with a plurality of solutionswhich react therein to precipitate any desired diluent-s.

(8) Soluble diluent compounds may be added to the components forming abase exchange body, which, after formation, retains.

the compounds in solution and is dried without washing, or is treated toprecipitate the compounds.

(9) Naturalbase exchange bodies or artificial base exchange bodies,diluted or undiluted, or their derivatives, may be impregnated withsolutions of the desired compounds, which are then precipitated by meansof reactive gases.

The nucleus or non-exchangeable portion of the molecules of the baseexchange bodies is ordinarily considered to consist of two types ofoxides, namely, relatively basic metal oxides, usually amphoteric, andrelatively acidic oxides, such as SiO ,,some amphoteric metal oxides andsome metal oxideswhich have a distinctly acid character. he nucleusbehaves as a single anion and cannot be split by ordinary chemicalmeans, but it is advantageous to consider the two portions of thenucleus as the basic and acidic portions,

bearing in mind of course that the nucleus behaves as a single group.The metal compounds which are capable of forming the basic portion ofthe nucleus are thoseof the following metals: copper, silver, gold,bismuth, beryllium, zinc, cadmium, boron, aluminum, some rare earths,titanium, zirconium, tin, lead, thorium", niobium, antimony, tantalum,chromium, molybdenum, tungsten,

uranium, vanadium, manganese, iron, nickel, cobalt, platinum, palladium.Compounds of these elements'may be introduced singly or in mixtures, inany desired proportions, and may be in the form of simple or complexions. It should be understood that some of the elements in certainstages of oxidation may be introduced either as metallales or metalsalts; others may be introduced in only one form,

and still others may be introduced in a stage of oxidation other thanthatdesired in the final base exchange body, or in the form-of complexcompounds. Among the complex ionogens are ammonia, hydrocyanic acid,0xalic acid, formic acid, tartaric. acid, citric acid, glycerine, andthe like. i v

. Many of the metals are specific catalysts, others are stabilizers, andstill others are stabilizer promoters. of an elementas catalyst orstabilizer promoter will vary with the particular reaction for which thefinal contact mass is to be used, and the choice of catalysts andstabilizer, promoters, together with the proportions, will be determinedby the particular organic deamination reactionv for which the contactmass is to be used. I 7

Examples of components forming the relatively acid portion of the baseexchange nu-' cleus are alkali metal silicates which are soluble inalkali, and alkali metal salts of acids, such as those of boron,phosphorus, nitrogen,

The exchangeable bases of the base ex- Naturally the status changebodies may be substituted by base exchange, and the elements which canbe introduced singly orin admixture by base exchange are the following:copper, silver, gold, ammonium, beryllium, calcium, manganese, caesium,potassium, sodium, zinc, strontium, cadmium, barium, lead, alumium,scandium, titanium, zirconium, tin, antimony, thorium, vanadium,lithium, rubidium, thallium, bismuth, chromium, uranium,

manganese, iron, cobalt,fnickel, ruthenium,

palladium, platinum and cerium.

Depending on the reactions in which-the contact mass is to be used, theexchangeable bases introduced maybe specific catalysts, they may bestabilizers, or they may be stabilizer promoters.

tact mass, improveits physical strength, or both. l

As hasbeen described above, base'exchange bodies can be causedto reactwith compounds containing-acidic radicalscapable of forming therewithsalt-like bodies; The radicals may be present in the form of simpleacidradicals,

polyacid radicals or complex acid radicals, and include radicalscontaining the followin elements :'.chromium, vanadium, tungsten,

They may be introduced as simple ions or as complex ions, and mayenhancethe catalytic activity of the finalcon uranium, molybdenum,manganese, tantalum, niobium, antimony, selenium, tellurium, phosphorus,bismuth, tin, chlorine, platinum, boron. Among the complex radicals areferroand ferricyanogen, certain ammonia complexes and the like. Theamount of acid radicals caused to unite with the base exchange bodies toform salt-like bodies may be varied so that the resulting products maypossess the character of acid, neutral or basic salts. Many of theseacid radicals are stabilizers or stabilizer promoters for thedeamidation of organic compounds.

The base exchange bodies, diluted or undiluted or some of theirsalt-like body derivatives, may be treated with acids, such as mineralacids, for example, 2-1070 sulfuric, hydrochloric or nitric acids, toremove part or all of the exchangeable bases, or also part or all of thebasic portion of the nucleus.

In the case of zeolites, the partial leaching with acids, which leavespart or all of-the basic portion of the nucleus or even part of theexchangeable bases, does not affect the function of the zeolites ascatalysts when they contain catalytically active elements in the basicportion of the nucleus, or in some cases even exchangeable bases, andsuch partially leached catalysts are of great importance in manyreactions. Where the leaching is carried out to completion theadvantageous physical structure remains to a considerable extent'thesame but the remainder is of course a form of silica, or, in the case ofzeolites in which part ofthe silica is replaced by other acidiccompounds, a mixture of the two and usually will not be a specificcatalyst for the reactions of the present invention. It serves, however,as an advantageous physical carrier of specific catalysts, and in thecase of partially substituted zeolites may also contain stabilizerpromoters,

Leached non-silicious base exchange bodies, either partially orcompletely leached,

may containcatalytically active components and behave as catalysts,stabilizer promoters,

or both, and'many important catalysts are thus obtained. This isparticularly the case for reactions where a relatively alkali-freecontact mass is required for best results and where the alkali contentof acontact mass containing a'base' exchange body may be too great foroptimum results.

' Base exchange bodies or their derivatives, diluted or undiluted, mayalso be coated in the formof films on massive carrier granules or may beimpregnated therein. The massive carriers may be inert, activating, orthemselves catalysts. For example, certain catalytic metal alloys andminerals fall within this class. Aluminum or copper alloy granulesperform an additional advantageous function in that theirrelatively highheat conductivity tends to prevent local overheating-in exothermicreactions, which is of considerable importance in obtaining goodyieldsof the product. 7

Eaqample 22 parts of basic copper carbonate are dis-' solved in the formof a cuprammonium com pound by means of 10% ammonia water.

10.2 parts of freshly precipitated aluminum hydroxide are dissolved upin sufficient 2 N. sodium hydroxide solution to form a clear sodiumaluminate solution, and, finally, 2% parts of copper nitrate containing3 mols of water are dissolved in 100 parts of water. The cuprammoniumcarbonate andthe sodium aluminate solutions are then mixed together and50 parts of l'rieselguhr are introduced with vigorous agitation.Sufficient copper nitrate solution is then poured intothe mixture withvigorous stirring until a gelatinous blue product separates out,thereaction being neutral or slightly alkaline to phenolphthalein. Theproduct is a non-silicious base exchange body containing sodium, copperand aluminum, and is dilutedwith materials rich in SiO The gel ispressed and dried, preferably at temperatures not exceeding 100 0.,broken into fragments and hydrated with water. The contact mass is thenready for use, but it is advantageous in some cases to leach thehydrated base exchange body before drying for a short time in ordertoremove part of the exchangeable alkali. The leaching may be effected bytrickling 1 to 2% nitric acid over the mass. After leaching the productis again dried and constitutes a well toned contact mass fordehydrogenations. 7 Before use the contact mass may advantageously begiven a preliminary treatment with hydrogen containing gases at 300 C.

Aniline vapors are passed over the contact mass at temperaturespreferably between- 200 tO0 G., diphenylam'ine being produced as themain product. V

The base exchange body produced by fusing a mixture of 5 mols Na CO 1mol A1 03, 3rmols TiG and 1 mol borax iscarefully leached With Warmwater'and then-treated with a normal thorium nitrate solution in orderto introduce a maximum of thorium oxide by base exchange. After dryingthe body is leached with dilute' nitric acid in order to remove amaximum of the remaining alkali.

This base exchange body may be used asis or i transformed intodiphenylamine or the other corresponding secondary amines.

The deaminations have been described as being carried out at ordinarypressure which is the most economical in the majority of cases. However,the reactions may be carried out at elevated pressures or under avacuum.

This application is in part a continuation of my prior applicationSerial No. 267,134, filed April 3, 1928.

In the claims the term permutogenetic covers base exchange bodies,silicious or nonsilicious, the products obtained by the acid leaching ofthese base exchange bodies and the salt-like bodies obtained by thereaction of these base exchange bodies with compounds the acid radicalsof which are capable of reacting With the base exchange bodies toproduce products which show most of the properties of salts. When usedin the claims, the term permutogenetic Will have no other meaning.

What is claimed as new is:

1. A method of transforming an aromatic primary amine into a secondaryamine, which comprises vaporizing the primary amine and subjecting thevapors at reaction tempera-- tures to the action of a contact masscontaining a permutogenetic body.

2. A method of transforming an aromatic primary amine into a secondaryamine, which comprises vaporizing the primary amine and subjecting thevapors at reaction temperatures to the action of a contact masscontaining a diluted permutogenetic body.

3. A method of producing diphenyl amine from aniline, which comprisesvaporizing the aniline and subjecting the vapors to the action of acontact mass containing a permutogenetic body at temperatures of200-6200 0.

L. A method of producing diphenyl amine from aniline, which comprisesvaporizing the aniline and subjecting the vapors to the action of acontact mass containing a diluted permutogentic body at temperatures of5. A method accordingto claim 1 in which at least one catalyticallyeffective component of the contact mass is present in thepermu-togenetic body in non-exchangeable form.

6. A method according to claim 3 in which at least one catalyticallyeffective component of the contact mass is present in the permutogeneticbody in non-exchangeable form.

Signed at Pittsburgh, Pennsylvania, this 28th day of March, 1929.-

ALPHONS 0 J AEGER.

